Objective: The purpose of this study was to examine whether a common, non-invasive, muscular fitness field test was a better predictor of bone strength compared to body mass. 

Methods: Hierarchical multiple regression analyses were used to determine the amount of variance that peak power explained for bone strength of the tibia compared to body mass. Peak power was estimated from maximal vertical jump height using Sayer’s equation. Peripheral quantitative computed tomography scans were used to assess bone strength measures. 

Results: Peak power (ꞵ=0.541, p<0.001) contributed more to the unique variance in bone strength index for compression compared to body mass (ꞵ=-0.102, p=0.332). For polar strength strain index, the beta coefficient for body mass remained significant (ꞵ=0.257, p<0.006), however, peak power’s contribution was similar (ꞵ=0.213, p= 0.051).

Conclusion: Compared to body mass, peak power was a better predictor for trabecular bone strength but similar to body mass for cortical bone strength. These data provide additional support for the development of a vertical jump test as a simple, objective, valid and reliable measure to monitor bone strength among youth and adult populations.

Recruitment and Participant Characteristics: 

A convenience sample of 142 participants (79 F, 63 M)  (13.3% African American/Black, 17.9% Latina/o, 28.6% White, 27.6% Asian/Pacific Islander, 1.0% American Indian or Alaskan Native and 11.7% Mixed Race or Unknown) was recruited for this observational, cross-sectional study, from the faculty, staff, and students at a mid-sized regional university.  Participants were recruited through flyers, emails to the university community, and word-of-mouth advertisement. Participants received no compensation for participation. A general health and demographic survey was completed by all participants prior to the start of data collection to determine age, sex, and ethnicity of the participants. Participants were excluded if they had a history of any diseases that might influence bone health (endocrine diseases, gastrointestinal disorders, and eating disorders), were under 18 years of age, smoked, or were pregnant. All participants were informed of the risks and benefits of the study and provided written informed consent.  The study was approved by the California State University, East Bay Institutional Review Board (IRB) (CSUEB-IRB-2016-223-F). The study was pre-registered at the Center for Open Science OSF (DOI: 10.17605/OSF.IO/B5QZC).

Peripheral quantitative computed tomography (pQCT) (XCT 2000 Stratec Medizintechnik, Pforzheim, Germany) scans were used to assess bone strength measures of the dominant tibia.  Maximal jump height was measured using a Vertec™ (JUMPUSA.com, Sunnyvale, CA).